public class test02 {
    /**
     * Definition for a binary tree node.
     * public class TreeNode {
     *     int val;
     *     TreeNode left;
     *     TreeNode right;
     *     TreeNode(int x) { val = x; }
     * }
     */

        public TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) {
            //二叉搜索树，根据性质，更简单
            if(root.val>p.val && root.val>q.val){
                return lowestCommonAncestor(root.left,p,q);
            }else if(root.val<p.val && root.val<q.val){
                return lowestCommonAncestor(root.right,p,q);
            }
            return root;
        }
}
